Grand piano



I. H. WILLIAMS.

GRAND PIANO.

APPLICATION FILED MAR. 5. 1920.

Patented May 16, 1922.

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1. H. WILLIAMS.

GRAND PlANO.- APPLICATION FILED MAR. 5- 1921}.

Patel lted May16, 1922.

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air/ms UNITED STATES PATENT OFFICE.

JAMES H. WILLIAMS, 0 BALTIMORE, MARYLAND.

GRAND PIANO,

Application filed March 5,

To all whom it may concern Be it known that I, JAMns H. WILLIAMS, a citizen of the United States, residing at Baltimore, in the county of Baltimore City and State of Maryland, have invented new. and useful Improvements in Grand Pianos, of which the following is a specification.

My present invention relates to improve ment in pianos, and more particularly to those of the so called grand or baby-grand type, having an interior bracing structure or frame below the sound board-thereof, which brace structure or frame comprises a transverse member to which the front edge of the sound board is attached, and also to those of thetype referred to comprising a transverse 'member such as that described,

and a number of divergent or diagonalbraces which extend from the transverse member to the periphery of the inner frame. The primary object of the invention is to provide the transverse member or the trans verse member and some or all of the braces with interiorly formed air chambers, which are located adjacent to the sound board and have openings or ports leading to the ex terior thereof, these interior air chambers constituting relatively long air columns which are set into vibration by the adjacently located sound board,'the sound board being set into vibration by the strings, and the latter being set into vibration by the hammers. In consequence ofthe resonance afit'orded by this air chamber, the volume and the duration of the tone are increased, and the fullness and other qualities of the tone are improved.

To these and other ends the invention consists incertain'improvements, and combination and arranged parts all as will be hereinafter more fully described, the features of novelty being pointed out particularly inthe claims at the end of the specification.

In the accompanying drawings z- Figure 1 represents a section taken longitudinally through a grand piano provided with resonance or air chambers in accordance with the preferred embodiment of the invention, the section being on line 1-1 of Figure 2; and Figure 2 represents a top plan view of the inner frame the transverse member and Specification of Letters Zatent.

Patented May '16, 1922.

also variations in. the construction may be made in applying the invention to the different interior constructions of the supports or braces of the various pianos of'the type described.

In the present-instance, wherein the invention is shown applied to a grand piano, the interior supports and braces of which are of well-known construction, 1 designates the outer; case which encloses the various parts or elements of the piano, the case having a lid'2 as usual, 3 designates the key board, and 4: designates the action which may be, of the usual or any suitable type which operatesin response to the key board to strike the strings 5 to set the same into vibratiouin the well-known manner. The strings are carried" as usual by an iron framed I The interior supports or braces, as shown in the present instance comprise a transverse member 7, and the radial or angular braces 8, which extend from the transverse member 7 to different parts of the peripheral portion 9 of the inner frame, it being understood that the ends of the transverse member 7 are also secured to the oppositesides of the peripheral portion 9 of the inner frame, and that the inner frame is enclosed by the case 1. According to the present invention, the transverse member 7, or the transverse member 7 and also some or all of the braces 8 are provided with interior air chambers, which are located in close relation to the sound board, and define air columns which are set into vibration by the adjacently located sound board. In the present instance these air chambers are provided by forming a groove 10 in the top of the transverse boarc to points near the ends of the transverse member 7. Communication is provided between these grooves 10 and the exterior of the transverse member by extending a. suit able number of openings through the wall of the roove, a pair of these opening:-; being siown in the present instance as ex tended through the front wall. of the groove. In pianos using a transverse member such as the member 7, but without braces such as the braces 8, the air chamber in the transverse member 7 will be sufficient to materially increase the volume and duration of the tone and to improve the quality of the tone. Where, however, braces such as the braces S are used, air chambers are also preferably provided therein, and in providing air chambers in the braces, it is pref erable to arrange these air Cilitl'fllDGlS in the braces so that they intercommunicate with the air chambers 10 formed in the cross member. The air chambers are preferably provided in the braces by forming a groove 12 in the top of the brace, the groove of each brace extending from the groove 10 in the cross member 7 to a point near the opposite end of the brace, and the top of each groove is covered by a relatively thin strip 13, preferably of wood which is glued to the top of the brace. Suitable means of communication is provided. between the groove in-each brace and the exterior, it being preferable to provide an opening or vent l t in the side wall of each groove at a point near the point of attachment of the respective brace to the periphery 9 of the inner frame. The top of the groove 10 in the cross member 7 is covered by a strip 15, it being of such a height as to bring its upper surface even with the upper edge 16 of the periphery 9 of the inner frame. The sound board 17 is glued to the top of the strip 15, and to the upper edge 16 of the peripheral portion 9 of the inner frame, the sound board having the main or bass bridges 18 and 19 glued or otherwise mounted on its upper surface, the strings 5 being stretched over these bridges in the usual way.

The strip 15 constitutes a batten for the sound board and, as such, is a part of the sound board.

By the construction described air chambers are provided within the interior frame consisting of supports or braces of the piano, and these air chambers are located closely adjacent to the vibratory sound The air chambers described define air columns of substantial size and length, and these air columns are set into vibration from the sound board, the sound board in turn being set into vibration from the strings incident to the striking of the strings by the hammers. The resonance obtained. by these aircolumns or air chambers amplifies the volume of the tone, it prolongs the duration thereof after the striking of each string, and it imparts a greater breadth or fullness to the tone, and otherwise improves the quality thereof.

1 claim as my invention I. In a grand piano, the combination of transverse frame member having a groove formed therein, a strip covering said groove and forming a wall for closing the same, said groove having outlets and constituting an air chamber responsive to exterior sound waves, and a sound board mounted at its front edge on said strip.

2. in a grand piano, the coi'nbination with a frame having peripheral and transverse members of which the latter is provided with a longitudinal groove formed in the upper side thereof, a strip secured to said memberin covering relation to the groove, lateral openings being provided in communication with the groove, and a sound board bearing at its front edge on said strip and at its sides and rear portion on the said peripheral member.

8. In a grand piano, the combination. of a transverse frame member to support the front edge of the sound board and braces extending from said member, the transverse member and braces having comnmnicating interior air chambers.

41:. in a grand piano, the combination of a transverse frame member, braces extending therefrom, said member and braces having grooves formed in their upper sides, strips applied to the upper sides of said transverse member and b aces to cover the grooves therein, and a sound board extending over the grooved faces of saidtra-nsverse member and braces and secured at its front edge to the exposed surface of the strip on the transverse member.

in a grand piano, the combination of a transverse frame member, braces extending therefrom, said member and braces having grooves formed in their upper sides, strips applied to the upper sides of said trans verse member and braces to cover the grooves therein, and a sound board extending over the grooved faces of said transverse member and braces and secured at its front edge to the exposed surface of the strip on the transverse member, the grooves in the transverse member and braces being in communication.

6. In a grand piano, the combination of a transverse frame member, braces extending therefrom, said member and braces hav- 'ing grooves formed in their upper sides, strips applied to the upper sides of said transverse member and. braces to cover the grooves therein, and a sound board extending over the grooved faces of said transverse member and braces and secured at its front edge to the exposed. surface of the strip on the transverse member, the grooves in the transverse member and braces being in communication and having lateral outlets. 7. A. grand piano, having a transverse frame member and a sound board supported thereby, said member being provided in the side facing the sound board With a longitudinal terminally closed channel defining a column of air, and having lateral outlets,

In testimony whereof I have hereunto set my hand in presence or" a subscribing Witness.

JAMES H. WILLIAMS.

Witness C. A. BATEMAN. 

